The TLD was formerly administered by Planet Three Limited, a company with offices in the United Kingdom and Australia, which went bankrupt and ceased operations, voluntarily transferring management to CIIA (called Dot CX Limited at the time). The local (shire) government of Christmas Island endorsed the transfer, but the Commonwealth of Australia (which has international authority over Christmas Island as an external territory) did not immediately approve it. Australia has since published a Memorandum of Understanding which recognizes CIIA as the legitimate manager of .cx.

The domain achieved a certain degree of notoriety when it was used for the shock sitegoatse.cx, to the point the CIIA was forced to take down the website following complaints by Christmas Islanders.[1]